Manufacture of soles



Jan. 17, 1939. w. D. THOMAS MANUFACTURE OF SOLES Filed Jan. v16, 1935 2 Sheets-Sheet l Jan17,1939 y WDTHOMAS 2,144,285

' MANUFACTURE oF SOLES Filed Jan. 1e, 1935 2 sheets-sheet 2 Patented Jan. l?, i939 PATENT OFFICE MANUFACTURE` OF SOLES William D'. Thomas, Lynnfeld, Mass., assignor to United Shoe Machinery Corporation, Paterson, N. J., a corporation of New Jersey Application January 16, 1935, Serial No. 2,088

lll Claims.

This invention relates to the manufacture of soles for shoes .and is herein illustrated with reference to the manufacture of insoles and outsoles having complemental forepart portions.

In the manufacture of shoes of a well-known type, it is customary to form from an integral leather sole blank a skeleton insole having an l opening in its forepart and an outsole having a raised portion or projection on its forepart which is complemental to the opening in the insole. This practice necessitates the use of a sole leather blank of a superior quality of leather suitable for the making of an outsole and of a thickness equal to the combined thickness of the outsole and the insole which are to be made therefrom. Sole leather of such quality and thickness is necessarily expensive and is not always readily available and it is among the objects of the present invention to render unnecessary the employment of such sole leather in the manufacture of insoles and outsoles of the type referred to and to effect a substantial reduction in the cost of such manufacture.

To the accomplishment of this object the present invention provides an improved method of making soles which, as herein exemplified, involves the securing together of the central forward portions only of a relatively thin insole blank and a relatively thick outsole blank to make a laminated blank having a relatively thin ply or insole layer and a relatively thick ply or outsole Iayer, and cutting through the insole layer around that portion which is secured to the outsole layer thereby separating the two layers and providing a thin skeleton insole having an opening in its forepart and a thicker outsole having secured to the central portion of its forepart a projecting portion complemental to the opening in the insole.

This cutting operation may conveniently be accomplished, as illustrated, by means of a matrix roll splitting machine comprising a single straight-edged splitting knife and cooperating matrix rolls constructed and arranged to feed a sole blank edgewise to and past the knife and to deform the blank from its normal flat condition before it reaches the knife in such a `manner as to control the location of the cuts so that the desired result shall be obtained. Advantageously, the rolls may also be constructed and arranged to deform the marginal portions of the composite blank to different extents in the forward and ,shank portions of the blank so that the splitting knife will operate also to produce an outsole the margin of which is reduced in the forepart to compensate for the thickness of the upper materials of the shoe and is reduced in a different manner in the shank portion so as, for example, to provide a thin beveled edge in that location. The insole blank or layer may advantageously consist of leather of a less superior quality than that ordinarily employed in the manufacture of outsoles, or it may consist of a suitable leather substitute such as that commonly employed in making so-Called manufactured insoles thereby effecting a substantial saving in the cost of materials. It is to be noted, however, that even if both the insole and the outsole layers are cut from superior quality leather the cost of the material employed will still be substantially less l5 than that of an integral leather blank of' a thickness such that both an insole and an outsole may be formed therefrom in accordance with the customary practice hereinbefore referred to. 20

The invention will be explained with reference to the accompanying drawings, in which- Figs. land 2 are perspective views, respectively of a relatively thin insole blank and a relatively thick outsole blankshowing the blanks as they appear after their central forepart portions have been coated with adhesive preparatory to the assembly of the blanks in face-to-face relation;

Fig. 3 is a perspective view of the blanks above referred to after they have been assembled and their central forepart portions have been secured together to provide a single composite blank;

Fig. 4 is a fragmentary elevational view of a portion of a sole roundingmachine illustrating the operation of the machine upon the composite blank shown in Fig. 3;

Fig. 5 is a perspective view of the composite blank as it appears after it has been operated upon by the rounding machine;

Fig. 6 isa sectional view illustrating the operation of a matrix roll splitting machine upon the composite blank; l

Fig. 7 is a fragmentary View in vertical section of two matrix rolls showing portions thereof especially `designed for operation upon the forepart of the blank and showing also the work being operated upon;

Fig. 8 is a View similar to Fig. 7 but showing those portions of the matrix rolls which operate upon the shank portion of the blank; :50

Fig. 9 is a perspective View of a skeleton insole produced as a result of the splitting operation; and

Fig. 10 is a perspective view of an outsole produced as a result of the splitting operation.

In the manufacture of an insole and an outsole having complemental forepart portions: I employ two sole blanks such as the insole blank I4 and the outsole blank I6, the blank I6 being preferably of sole leather of a quality and thickness suitable for the production of an outsole and the blank I4 being preferably thinner than the blank I6 and being preferably composed of a less expensive material such, for example, as one of the well-known leather substitutes commonly used in the making of so-called manufactured insoles. The blanks I4 and I6 are to| be secured together by means of adhesive and it is preferred to secure them together only at the central portions of their foreparts so that the areas of the united or bonded surfaces shall correspond substantially to that of the base of the raised or projecting forepart portion which is to be formed upon the nally produced outsole and which is to be complemental to the opening in the forepart of the finally produced insole. With this end in view the sole blanks I4 and I6 are initially prepared, as herein illustrated, by having coatings of cement, for example rubber latex, applied to those portions only of their surfaces which are to be united, such coatings being shown at I8 and 20. It should be understood, however, that it is not by any means essential that the union between the two sole blanks shall be limited to their central forepart portions inasmuch as it may be found desirable under certain conditions to secure by means of adhesive substantially the entire forepart portions ofthe blanks or even to secure them together throughout their entire lengths. After the cement has been applied to one or both of the blanks, as the case may be, the blanks are assembled with their coated portions in face-toface relation and they are subjected to pressure and thereby the cement-coated portions of the two blanks become firmly united as indicated in Fig. 3, wherein 22 designates the cement layer between the bonded portions of the blanks and 24 indicates the boundary of the bonded areas. There has thus been produced a single composite sole blank 26 comprising two layers 28 and 33 (corresponding to the insole blank I 4 and the outsole blank I E, respectively), the layers having been firmly secured together at the central forepart portion of the composite blank but being1 separated in the heel and shank portions and also along the marginal portion of the forepart of the blank. The composite blank 26 is next rounded, for example, by means of a sole rounding machine. Preferably, but not necessarily, this rounding operation may be performed by means of a so-called double knife rounding machine such, for example, as that disclosed in United States Letters Patent No. 2,057,665, granted October 20, 1936, upon application of F. E. Bertrand, in order to impart to the layer which is finally to constitute the insole a desired sole-shaped contour somewhat smaller in certain of its transverse dimensions than the outline to be impartedto the other layer (which is finally to Iconstitute the outsole) and thus to provide space to receive the -upper materials which are to be lasted over the insole without causing the latter to project over the edge of the outsole. As indicated in Fig. 4, such a double knife rounding machine comprises upper and lower patterns 32 and 34 between which is located the work, herein illustrated as the composite sole blank 26, and upper and lower rounding knives 36 and 38 which are caused totravel around the edges of the patterns 32 and 34, respectively. In the use of the machine just described the lower rounding knife 38, following the contour of the pattern 34, will trim both layers of the composite sole blank and thus determine the final outline of the layer 3i) (which is to constitute the outsole) while the upper knife 36, following the contour of the pattern 32 which is smaller than the pattern 34, cuts downwardly through the upper layer 28 (which is to constitute the insole) along a path located Within the path of the lower knife 38, thus cutting the insole Vlayer somewhat smaller than the outsole layer.

After this rounding operation has been completed, the strip of waste material severed from the insole layer by the upper knife 35 may be readily removed inasmuch as it is not cemented to the outsole layer. The rounded sole blank then appears as shown in Fig. 5, wherein it will be seen that the edge of the insole layer 28 is spaced inwardly relatively to the edge of the outsole layer 30.

The rounded sole blank comprising the two layers 28 and 39, which, as hereinbefore described, are preferably secured together only at the central portions of their foreparts, is then. submitted to a splitting operation as a result of which a central opening is cut in the forepart of the layer 28, thereby producing a skeleton insole and leaving the portion which was cut out of the insole layer projecting from the surface of the outsole. If, however, the two layers constituting the composite blank have been cemented together throughout an area more extensive than that of its central forepart portion, the splitting operation, in addition to cutting through the forepart of the insole layer, will result in dividing the composite blank into two separate layers.

Advantageously, the splitting operation above referred to may be performed by means of a machine of the general type of that described in United States Letters Patent N o. 2,088,745, granted August 3, 1937, upon application of C. E. Hood. As indicated in Fig. 6, such a machine comprises a single, straight-edged splitting or skiving knife 42, an adjustable upper matrix roll 44, and a lower feed roll 46 which is yieldingly mounted so as to press the work, that is, the sole blank, toward the upper roll 44. The roll 44 has formed -therein a cavity 48 shaped in outline to correspond with that of the portion to be cut from the forepart of the insole and the roll is adjustable relatively to the knife 42 to determine the location of the split relatively to the upper and lower surfaces of the composite sole blank. In the machine of the application referred to the lower feed roll has no projection complemental to the cavity in the matrix roll but, in accordance with the more usual construction in matrix type splitting machines the lower feed roll may be provided with such a projection, as indicated at 5U in Fig. 7. Preferably, also, the upper roll 44 is provided with a projection 52 (see Fig. 7) and the lower roll 46 with a complemental recess 54 adapted to cooperate with the projection 52 to form upon the insole layer side of the composite sole blank, around the forepart of the latter, a projection`58 extending entirely around the marginal portion of the forepart of that blank. While being operated upon by the rolls 44 and 46 the composite sole blank is deformed as illustrated in Fig.

7, the blank having a depression or cavity 55 l also, around its forepart, the marginal projection 58 already referred to as being formed by the cooperative action of the projection 52 in the upper roll and the complemental recess 54 in the lower roll. As that portion of the sole blank which is being operated upon by the rolls 44 and ll is advanced past the knife 4Z (the cutting edge of which is conventionally indicated at 60 in Figs. 7 and 8), the knife cuts diagonally through the insole layer around its deformed centralY forepart portion, thereby producing a skeleton insole, such as that shown at 62 (Fig. 9) having a central opening 64 in its forepart and an outsole 66 (Fig. l0) having in its forepart a projection or raised portion @3 complemental tothe opening in the insole, the projection 68 being composed of leather substitute material cut away from the insole in forming the opening in the latter and being firmly secured to the outsole by the cement by means of which the central forepart portions of the two layers constituting the composite sole blank were initially secured tc;- gether. If the united areas on the insoleand outsole layers have been restricted to correspond in shape and location to that of the opening and projection which are to be formed in the insole and on the outsole, respectively, and if the upper roll ifi has been accurately adjusted so that the cutting edge oi the knife 42 lies exactly in the plane of the cement attached surfaces of the two layers 28 and 3l), this diagonal cut will be sufficient entirely to separate the insole layer from the outsole layer. If, however, these two layers 28 `and 3i! have been cemented together beyond the areas of their central forepart portions, the splitting knife will also operate to split the composite blank in, or approximately in, the plane of the cement attached surfaces of its component layers. In order to split the composite blank exactly in the plane of the cement joint between its layers a very accurate adjustment of the roll (i2 must be made but such accuracy of adjustment is not regarded as essential since ordinarily it will not be objectionable if one of the separated layers has, cement attached to it, a thin skiving or veneer of 'the other layer. After the material has had an opportunity to react from the deiorming pressure to which it was subjected by the matrix rolls the opening in the insole will be surrounded by a narrow area which will be beveled at the side of the insole which is to face the outsole, as

indicated at l0 in Fig. 9, while the projection 68 on the outsole will have its exposed marginal portion beveled, as indicated at 'l2 in Fig. l0. The splitting knife also cuts into the deformed marginal portion of the outsole layer around its forepart, reducing the latter in such a Way that after the sole material has reacted from the deforming pressure of the matrix rolls the margin of the outsole will appear as indicated at lt in Fig. l0, the reducing cut sloping downwardly and inwardly from the edge of the sole and leaving the sole edge itself substantially unreduced in thickness, although sufficient reduction is provided in the marginal portion of the outsole to compensate for the thickness of the upper materials which are to be overlasted upon the insole.

As indicated in Fig. 8, the matrix roll it may also be provided with a projection 16 and the roll it with a corresponding depression 78, the projection 'I6 and the depression 18 being adapted to cooperate to deform the margin of the shank or the shank and heel portions of the outsole so that the splitting knife will bevel the margin of the shank or the shank and heel portions of the outsole to a thin edge (Fig. 10) such as that usually desired in that portion of an outsole.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. That improvement in methods of making soles which consists in assembling in face-to-face relation a relatively thin sole blank and a relatively thick sole blank and securing them together at the central portions only of their foreparts, and thereafter separating the central forepart portion of said relatively thin blank from the rest of said blank, thereby providing a thin insole having a central opening in its forepart and a thicker outsole having in its forepart a projecting portion complemental to the opening in said insole.

2. That improvement in methods of making soles which consists in assembling in face-to-face relation two sole blanks, one of which is substantially thinner than the other and securing said blanks together at the central portions only of their foreparts, rounding said blanks to impart to each a sole-shaped contour, and thereafter cutting diagonally through the relatively thin blank around its central forepart portion to provide an insole having an undercut central opening in its forepart and an outsole having a beveled forepart projection complemental to the opening in the insole.

3. That improvement in methods of making soles which comprises applying adhesive to the central forepart portion only of at least one of two sole blanks, one of which is relatively thin and the other of which is relatively thick, assembling said blanks in face-to-face relation and applying pressure thereto thereby securing said blanks together and forming a single laminated blank consisting of a relatively thin layer and a relatively thick layer, cutting through said relatively thin layer around that portion thereof which is secured to said relatively thick layer, thereby separating the latter from the former, and `providing a thin skeleton insole having an opening in its forepart and a thicker outsole having secured thereto a projecting portion complemental to the opening in said insole.

4. That improvement in methods of making soles which comprises applying adhesive to the central forepart portion only of at least one of two sole blanks, one of which is composed of relatively superior material and the other of which is composed of relatively inferior material, assembling said blanks in face-to-face relation and applying pressure thereto, thereby providing a single composite blank consisting of a layer of relatively superior quality material and a layer of relatively inferior quality material, said layers being united only at the central portion of the forepart of said composite blank, trimming said composite blank substantially to nal peripheral contour, cutting through said relatively inferior quality layer around that' portionthereof which is secured to said relatively superior quality layer, thereby separating the latter from the former, and providing a skeleton insole of relatively inferior quality material having an opening in its forepart and an outsole of relatively superior quality material having secured thereto a projecting portion of said relatively inferior quality material complemental to the opening in said insole.

5. That improvement in methods of making soles which comprises securing together the central forepart portions only of two sole blanks, one of which is relatively thin and the other of which is relatively thick, thereby providing a single 1aminated blank comprising a thin layer and a thicker layer, trimming said thin layer to a relatively small sole-shaped contour, trimming said thicker layer to a relatively large sole-shaped contour, and thereafter cutting through said thin layer around that portion thereof which is secured to said thicker layer, thereby sep-arating the latter from the former, and providing a thin skeletonized insole having an opening in its forepart and a relatively thick outsole having secured thereto a projecting portion complemental to the opening in said insole.

6. That improvement in methods of making soles which comprises assembling a relatively thick sole blank in face-to-face relation with a relatively thin sole blank, securing together the central portions only of the foreparts of said blanks, reducing the thickness of the marginal portion of said relatively thick blank and, simultaneously with a portion of said reducing operation, cutting through the forepart of said relatively thin blank around that portion which is secured to said relatively thick blank, thereby separating the latter from the former, and providing a thin skeletonized insole having an opening in its forepart and a thicker outsole having a reduced marginal portion and having secured to the central portion of its forepart a projecting portion complemental to the opening in the insole.

7. That improvement in methods of making soles which comprises assembling face-to-face a leather sole blank and a manufactured sole blank and securing together the central portions only of the foreparts of said blanks by means of adhesive, and cutting through the forepart of said manufactured blank around that portion which vis secured to said leather blank, thereby separating the latter from the former and providing a manufactured insole having a skeleton forepart and a leather outsole having secured thereto a projecting forepart portion of manufactured sole material complemental to the opening in said insole.

8. That improvement ingmethods of making soles which comprises assembling face-to-face a leather sole blank and a manufactured sole blank and securing together the central portions only of the foreparts of said blanks, cutting through the forepart of said manufactured blank around that portion which is secured to said leather blank, thereby separating the latter from the former and providing a manufactured insole having a skeleton forepart and a leather outsole having secured thereto a projecting forepart portion of manufactured sole material complemental to the opening in said insole, and simultaneously with said cutting operation reducing the thicknessl of the marginal portion ofthe outsole to compensate for the thickness of upper materials to be overlasted thereon. l

9. That improvement in methods of making soles which comprises assembling in face-to-face relation two sole blanks one composed of relatively high quality material and the other of relatively low quality material, securing together the central forward portions only of said blanks, deforming said sole blanks by depressing the central forward portions thereof relatively to the outer surface of said low quality layer, and while the sole blanks are thus deformed feeding them past a straight-edged skiving knife, thereby providing a skeleton insole having an opening in its forepart and an outsole having a projection in its forepart complemental to said opening, the deformation of the blanks being controlled so that the knife will cut through said relatively 10W quality layer around the central forward portion thereof.

10. That improvement in methods of making soles which comprises assembling in face-to-face relation a thin sole blank and a thicker sole blank, securing together the central portions of the foreparts only of said blanks, deforming said blanks by depressing the central forepart portions thereof relatively to the outer surface of said thin blank and raising the marginal portions of said blanks relatively to said surface, and while the blanks are thus deformed feeding them past a straight-edged skiving knife thereby cutting around the central portion of said thin blank and thereby providing a thin skeleton insole having an opening in its forepart and a thicker outsole having a projection in its forepart complemental to said opening and also reducing the thickness of the marginal portion of the outsole to compensate for the thickness of upper materials subsequently to be secured in overlas'ted relation to said outsole.

11. That improvement in methods of making soles which comprises securing together an insole blank and an outsole blank in their central forward portions only thereby providing a composite blank consisting of a layer of insole material and a layer of outsole material, feeding said composite blank past a straight-edged skiving knife and during the feeding deforming the blank by depressing its central forward portion relative to one surface of the blank and also raising the margins of the forepart and shank portions of said layers to different extents relative to said surface thereby causing said knife to out through said insole blank around said central forward portion thereof and thus to divide said blank into a skeleton insole having an opening in its forepart and an outsole having a projection on its forepart complemental to said insole opening and also to skive said raised margins of said layer of outsole material so as to produce a reduced marginal portion in the forepart of said outsole and a marginal portion reduced to a different extent in the shank portion of said outsole.

WILLIAM D. THOMAS. 

